Serous Cystadenocarcinoma of the Pancreas
Definition
-
Same histologic features as serous microcystic adenoma but with metastases or invasion of adjacent organs
Note:
- WHO 2010 defines requires distant metastases for this diagnosis but cites literature (Galanis 2007, King 2009) that defines malignancy as above
- It appears that invasion of adjacent organs is predictive of (infrequent) later metastases
- Even with distant metastases there are no reports of deaths due to carcinoma
Diagnostic Criteria
- Same histologic features as serous microcystic adenoma
- Innumerable small cysts
- Most 1-5 mm
- Scattered larger cysts
- Sponge-like / honeycomb appearance
- Most 1-5 mm
- Lined by single layer of flattened or cuboidal cells with clear cytoplasm
- Abundant glycogen (PAS +, diastase digestible)
- Rarely eosinophilic cytoplasm
- Occasional intracystic papillary projections
- Bland cytology
- Round/oval nuclei
- No mitotic figures
- At most, mild cytologic atypia
- Central stellate scar frequently present
- May calcify
- Scant stroma otherwise
- Occasionally entraps other elements
- Innumerable small cysts
- Must demonstrate vascular invasion, metastases or invasion of adjacent organs (see note at top)
- May be otherwise circumscribed
- Most metastases reported to local lymph nodes and liver
- Commonly invaded organs include spleen and stomach
- Rare cases have been reported of resected non-invasive serous cystadenomas that recurred later with metastases
- No deaths reported due to carcinoma
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting, updates: 1/4/07, 1/4/12